What should you know about it? Besides being the first zoom lens with constant f/1.8 aperture …….
1. The lens works only on APS-C body. This is indicated by the ‘DC’ in the product model name.

2. The lens as Hypersonic Motor. This is indicated by the ‘HSM’ in the product model name. HSM works like Canon’s USM – the motor in the lens for fast and silent focusing.

3. The lens does not have image stabilization.

4. The focal length is 27-52.5mm equivalent (after APS-C factor considered. Just multiply it by 1.5 for Nikon or 1.6 for Canon). This means Canon users a little bit more zoom.

5. Only available for Canon, Nikon and Sigma mounts.

6. This lens has internal focusing / zooming. 🙂 Really neat stuff. This means the lens does not extend the barrel when you focus or zoom.

7. In reference to point #6, this means the lens also does not have rotating front element. Ideal for CPL users.

Is this lens for you?

Here’s what you can do. Take your 18-55 lens …….. what? you don’t? You should. 🙂 The basic 18-55 lens are great as backup lenses! Anyway I digress, anyway just use your 18-55 (or 18-105, 18-135, 18-200……….) and you’ll get the feel of how wide you can go when the lens is at 18mm. After that, twist the zoom barrel to around 35mm. You’ll get a picture of how far the 18-35 can zoom.

It’s not great, some people say it’s a “neither here nor there” zoom range but I disagree. Canon users have been using 17-40 and 16-35 lens on APS-C bodies for ages with no issues. If you find the range is limiting, then looks like this lens is not for your. Either that or you just have to adapt your style to it.